Thermochemistry Introduction
Textbook Reference: Section 5.1

A Few Terms...

Thermodynamics: Study of energy, particularly that of conversion between heat and other forms of energy

Thermochemistry: Study of the energy changes that accompany physical or chemical changes in matter

Enthalpy: Heat content of a system

Calorimetry: the technological process of measuring energy changes in a chemical system by measuring the heat change in the surroundings of the system in which the change happens

Group Activity:
Simulation of calorimetric measure of enthalpy change of three types of system changes


Procedure:

1) Divide class into three groups of 6-7

2) Each group is to represent the calorimetric reading of the surroundings of a type of exothermic change
a. Physical change: change of state (water) from gas to liquid (i.e. condensation) –little heat transfer
b. Chemical change: Combustion –moderate heat transfer
c. Nuclear change: hydrogen fusion – HUGE amount of heat transfer

3) Role of students: to act as particles in the isolated surroundings of exothermic reactions/changes. When the change occurs, they are to move accordingly and relatively (to each other) to represent the kinetic energy of these surrounding particles.

4) Take temperatures: low change for physical, medium change for chemical, VERY HIGH for nuclear (level of excitation)

5) Explain: After taking mass and specific heat capacity into the equation (q=m*c*deltaT), one can calculate the enthalpy change of a system (although this method would not work for large nuclear reactions)

6) All chemical reactions involve enthalpy change -- an important concept in chemistry